In recent years, consideration has been given to global environmental problems such as of global warming phenomena, for which there have been expected practical applications of solar cells that are a clean energy source wherein no petroleum recourse is burnt.
Of such cells, organic solar cells have been being studied and developed because their ease in providing a large-sized area and low costs are expected (Patent Document 1: JP-A 2004-342693, and Patent Document 2: JP-A 2004-349657).
A variety of organic solar cell structures have been now proposed, and the trend of the studies and developments is to improve a photoelectric conversion efficiency, to improve charge separability, and to secure the stability of electronic device.
One of electrode materials of organic solar cells includes titania (titanium dioxide), and it is known that this material functions as an n-type semiconductor and is useful as one member of bulk heterojunction devices (Patent Document 3: JP-A 2005-236278).
An existing organic film in conjunction with this titania is only built up on the titania and is poor in interfacial adhesion with titania, with the attendant problem that the photoelectric conversion efficiency is not improved.
However, no molecular design of organic compound has never been made for the purpose of improving adhesion between titania and the organic film.
By the way, phthalocyanine compounds are long known as a dye or pigment that assumes a blue to green color.
Phthalocyanine compounds used as a functional dye have been employed in a diversity of fields, and an instance used as one of members of organic solar cells has been reported (Patent Document 4: JP-A 2002-83979).
However, this compound has never been subjected, up to now, to molecular design of improving affinity for and adhesion with titania as set out above.    Patent Document 1: JP-A 2004-342693    Patent Document 2: JP-A 2004-349657    Patent Document 3: JP-A 2005-236278    Patent Document 5: JP-A 2002-83979